#include<iostream>
#include<string>
#include<vector>
using namespace std;

class Solution {
public:
    int search(vector<int>& nums, int target) {
        int N = nums.size();
        int left = 0, right = N - 1;
        while (left <= right) {
            int mid = (left + right) / 2;
            if (nums[mid] > target) {
                right = mid-1;
            }
            else if (nums[mid] < target) {
                left = mid+1;
            }
            else
                return mid;
        }
        return -1;
    }
};

int main() {
    vector<int> nums = { 5 };
    Solution s;
    int ans=s.search(nums, 5);
    cout << ans << endl;
}